Mounting stencil screen and impressing a stencil therein



Oct. 20; 1942. 1.. H. Jol-lNso Bi "ErAL 2,299,628

MOUNTING STENCIL SCREEN AND IMPRESSiNG A STENCIL THEREIN med July 19,1940 2 Sheets-Sheet 1 in Men fora m Lyman ffJo/mson Pau/fi-Johnson 1941L. H; JOHNSON ETAL 2,299,628

MOUNTING STENCIL SCREEN AND IMPRESSING A STENCIL THEREIN Filed July 19,1940 2 Sheets-Sheet 2 [)7 ve forms 4 Zymcm HJo/mson Pau/ J-JoflnSonPatented Oct. 20, 1942 MOUNTING STENCIL SCREEN AND IMPRES S IN G ASTENCIL THEREIN Lyman H. Johnson and Paul S. Johnson, Los Angeles,Calif.

Application July 19, 1940, Serial No. 346,344

7 Claims.

In certain types of work a stencil is mounted upon a screen which inturn is secured over one of the open sides of a frame, forming in effecta container having the stencil upon one of the faces thereof. Suitablepigments are then placed within and upon the object to be stenciled inaccordance with the requirement of the job at hand.

And within the meaning of the word screen, it is to be noted that anytype of screen may be used, that is screens formed of metallic wire,spun glass or other material as well as perforated sheets of Celluloid,etc,

The preceding statement is introductory as to the type of workcontemplated and of itself is not new, being an accepted form ofoperationin certain types of work, however, past experience has shownthat it is quite diflicult to properly draw a screen taut upon the frameso that it lies in a substantially true horizontal plane without warpingor sagging upon being placed under strain, and this is particularly truewhen metallic screen is used, for in all of the operations involvingthis type of, screen apparatus,

pressure is placed upon one or the other of the I sides of the screenand such pressure while not great, but in the repetition nature thereof,causes the screen to become loosened from the frame and hence to sag andto become worthless in a short time for the purposes intended,

It may therefore, in view of the foregoing, be stated that a primeobject of the present invention is to provide a screen mounting in whichthe screen is held in a substantially horizontal plane under suchconditions of resiliency as to absorb the forces of motion and pressurewith a minimum. of wear and dislocation.

A further object of the invention is to provide means to mount a screenwherein the screen proper forms an island tautly supported upon a frameby means of an intervening sheet of material having elastic qualities.

A still further object of the invention contemplates the use of a screenof smaller lineal dimension than its supporting frame, wherein thescreen is brought into adhesion with surrounding elastic material whichis drawn taut and is secured to the supporting frame whereby the screenand the associated elastic material will lie in a substantiallyhorizontal plane.

A still further object of the invention is to provide a. stencil screensupport wherein the screen per se forms an island supported with sheetof fabric drawn taut with respect to the screen and frame and secured tothe frame.

A still further object of the invention is to provide a stencil screensupport wherein the screen per se forms an island supported with respectto a frame by means of an interposed sheet of rubber drawn taut withrespect to the screen and frame and secured to the frame.

A still further object of the invention is to unite a stencil type ofscreen, a frame, and elastic material whereby the screen will be tautlybut yieldably held in a horizontal plane.

And a still further object of the invention is to unite a stencil typeof screen, a frame, and an elastic material whereby the screen will betautly but yieldably held in a horizontal plane, in combination with astencil aflixed to the screen by the application of pressure so that thebody portion of the stencil is intertwined with the material of thescreen to form a unitary mass whereby increased life and durability ofthe stencil is obtained.

Other objects, features, and advantages of the invention may be observedfrom the accompanying drawings, the specification, and the accompanyingclaims.

In the drawings of which there are two sheets:

Figure 1 is a perspective or utility view of a screen mounting of thetype contemplated in the present invention.

Figure 2 is a detail, showing the first step used in development of thisinvention, wherein a sheet of elastic material is first drawn tautlyover a frame and upon which a sheet of metallic or other screen is layedflat upon the said sheet of material having elastic characteristics.

Figure 3 is a detail similar to Figure 2 except that here an elasticmaterial has been layed along one of the marginal edges of the top sideof the screen.

Figure 4 is a detail similar to Figure 3 except that here'a second stripof elastic material has been layed along the other of the marginal edgesof the top side of the screen, and of course parallel thereto.

Figure 5 is a detail similar to Figure 4 except that strips of elasticmaterial now cover the end portions of the screen intermediately of theparallel strips and overlapping the adjacent parallel strips.

Figure 6 is a sectional View taken along line 66, in Figure 5, showingthe relationship of the screen and the elastic material.

Figure 7 is a bottom View deleting lines of marespect toa frame" by'm'eans'of an interposed 55 teria'l abutment; and showing the materialin;

- material used is rubber, then the application of pressure is combinedwith heat to vulcanize the rubber into the mesh of the screen.

Figure 9 is a View of the bottom side of the device with a portion ofthe first layed sheet cut and removed from the face of the screen;

Figure 10 is a view of the device analogous to Figure 9, except that astencil has been placed upon the exposed screen preparatory to beingpressed into the mesh thereof.

Figure 11 is a bottom view of the finished screen mounting including theimpressed stencil.

In the drawings the reference character indicates the completed screenstencil support and impressed stencil of this invention, and comprises acustomary frame 22 of convenient shape having a screen 24 secured inposition thereon.

Insofar as appearance is concerned the general appearance of the product20 of this invention is similar to conventional screens used foranalogous purposes, however, reference to the succeeding figures of thedrawings indicates in progressive order definite departures from currentpractice in mounting the screen 24 upon the frame 22, and it is thismounting which comprises the present invention.

.In carrying out the construction of the screen mounting we prefer touse a, fabric such as silk as a suspension for the screen in ordinarywork, but for work having a surface formed with relatively high and lowspots or an undulatin surface, we use sheet rubber for the suspension,and as to this latter material it is to be noted that any materialhaving relatively great elastic quaiities may be used, such as certainty es of plastics in sheet form.

Use of fabric In using fabric material for a screen suspens'ion, wefirst draw the fabric across an open frame 22 and secure the same tautlythereon. The fabric thus placed upon the frame may then be marked forsubsequent placement of the screen 24, being usually centrally placedwith respect thereto.

That portion of the material 26 which lies between the edge of the frame22 and approximately V2 inch inwardly of the marked area is then coatedwith lacquer or other suitable blocking-'in material having bondingqualities, and after drying, the screen 24 is placed upon the markedarea and its marginal edges are taped in and affixed to the previouslylacquered portion of the sheet 26 by the application of more bondingmaterial. For the purpose of taping, any strong fabric may be used,however, preference is given to material having qualities similar tothose which comprise the sheet 26.

In building up the taped edges of the screen, reference is directed toFigure 3 wherein a fresh lacquered strip 28 is shown as being firstplaced upon the screen. Lacquer may again be freely applied to effect abond between the strip 28 and sheet 26. In Figure 4, we show a furtherstep, wherein a fresh lacquered strip 30 is placed upon the oppositeside of the screen, this strip is likepermitted to dry in the pressbefore being removed, being insulated from contacting the jaws of thepress by intervening sheets of paper or other material so as not toadhere thereto.

- After having been removed from the screen, a portion of the material,of the sheet 26 which lies over the screen 24 is removed as shown inFigure 9 so that the screen is now exposed upon both of its sides, andfurther and of vital importance is the fact that when a portion of thefabric is thus. removed, thetautly drawn material which remains upon thesides of the screen now pulls upon the screen, whereas the screen hadpreviously merely layed thereon, and this action draws the screen astautly as the fabric had previously been drawn. In other words tensionin the fabric is transferred in part to the screen and since the tensionis equally applied upon all of the sides of the screen and is equallyexerted in all directions the screen is held in a plane with the fabricacross the side of the frame to which it is secured, and the screen thusmounted is supported with a degree of elasticity which is proportionalto that of the fabric used as a suspension medium.

After the center of the fabric has been removed (Fig. 9) in definitionof an inner marginal edge 25, a gelatinous stencil 32 is placed upon theouter side of the screen 24. An absorbent sheet 2'! is preferably placedupon the opposite side of the screen, and on top of this sheet we placea sheet of rubber so that when the press 34 is worked the pressurethereof will force the material of the stencil into the mesh of thescreen. During this operation the absorbent sheet 21 takes up excessmoisture from the gelatinous stenciLwhile the rubber sheet 29 aids inforcing the stencil into the mesh of the screen, literally pressing thescreen and stencil into an integral mass, thereby ensuring that thescreen and stencil will not become dis-united in part or whole, thusgreatly increasing the useful life of the stencil. Stencils cut fromother materials may be more firmly attached or re-attached to the screenby slightly moistening the same with their proper solvent and thenplacing the stencil under pressure as above stated.

Use of rubber If sheet rubber is used in lieu of fabric, substantiallythe same procedure is followed in building the screen suspension as inthe case of fabric, excepting that after being built up the mass issubjected to heat and pressure to vulcanize the screen and rubbertogether. Thereafter a portion of the first layed sheet is removed as inthe case of fabric to transfer lateral tension from the sheet to thescreen. The stencil is applied in the same manner as aforementioned.

To describe the use of the screen of this invention is believed to beaside the point for there are many uses for a screen of this type, andsince we are only concerned with the mounting of the screen including astencil impressed thereon, at-

tention will only be directed to outstanding characteristics concerningthe same.

All screens of this type are subjected to varying kinds and degrees ofpressure from being brought into contact with the work to be stenciled,and this pressure because of its repetitious nature eventually causesthe screen to become frayed and to sag because it is not elastic in anyreal sense. However, with the mounting of this invention, the materialused to suspend the screen is possessed to elasticity and hence yieldssufficiently to absorb stresses otherwise imposed directly upon thescreen. In the case of fabric suspension the degree of elasticity isrelatively small and this type of mounting is best adapted forrelatively smooth work, that is, where the surface to be stenciled isrelatively smooth.

For rough work, that is, work having relatively high and low surfaceextremes or an undulating surface, the rubber type of screen suspensionis best adapted for its elastic qualities are far greater than silk orother fabric and hence readily accommodates itself to such conditions ofsurface irregularity without danger of developing sag or natural fatiguedue to excess tension.

Impressing the stencil in the mesh of the screen as aforestated greatlylengthens the life of the stencil for the screen and stencil are broughtinto such intimate relationship that it has been found that the stencilwill last a far greater length of time than if otherwise secured to thescreen, thereby effecting a saving in stencil replacement and timeinvolved in placing a new one in functional position.

The preceding statement covers our preferred screen suspension, however,it may be stated that various changes and modifications thereof may beeffected in practicing the invention in departure from the drawings anddescription as given, without however, departing from the true spirit ofthe invention as defined by the scope of the appended claims.

We claim:

The method of forming a support for a stencil which comprises securing asheet of elastic material upon a frame, then placing a screen upon saidsheet of elastic material, placing strips of elastic material upon allof the marginal portions of said screen including the sides thereof, thebonding of said strips and said sheet to the marginal portions of saidscreen with an adhesive, and the subsequent application of pressurethereto so as to force the elastic and bonding material into theinterstices of the screen, and then removing a portion of the sheet ofmaterial from lying over said screen.

2. The method of forming a support for a stencil which comprisessecuring a sheet of elastic material upon a frame, the placing of ascreen upon said sheet of elastic material, then placing strips of likematerial upon marginal portions of the sides of said screen, theapplication of a bonding agent to said strips and sheet of material tobind the same to said screen, the application of pressure thereto so asto force the elastic and bonding material into the interstices of thescreen for anchorage, then removing a portion of the sheet of materialfrom over the screen, and then impressing a stencil into the mesh of thescreen whereby the structure of the stencil is substantially mouldedthereto.

3. The method of forming a support for a stencil which comprisessecuring a sheet of elastic material upon a frame, the placing of ascreen upon said sheet of elastic material, then placing strips of likematerial upon marginal portions of the sides of said screen, theapplication of an agent having the characteristics of blocking-in theinterstices of said elastic material and of a bond whereby said sheetand strips of material will. adhere to said screen, the application ofpressure thereto so as to force the elastic materials and bonding agentinto the mesh of the screen, and then removing a portion of the saidsheet of material from over the screen whereby tension in the remainingportion of the sheet of elastic material is partially imparted to thesaid screen to hold the same taut.

4. The method of afiixing a gelatinous sheet stencil upon a tautly drawnscreen secured upon a frame, comprising the steps of applying agelatinous sheet stencil upon a face of said screen, the placing of anabsorbent sheet upon the opp0- site side of said screen, the placing ofa resilient sheet upon said absorbent sheet, and then applying asqueezing pressure thereto so as to force the gelatinous sheet stencilto flow inwardly of the face of the screen upon which it is situatedwhereby the wire of the screen is encased with the material of thestencil.

5. The method of affixing a gelatinous sheet stencil upon a tautly drawnscreen secured upon a frame, comprising the steps of applying agelatinous sheet stencil upon a face of said screen, the placing of anabsorbent sheet upon the opposite side of said screen, the placing of aresilient sheet upon said absorbent sheet, and then subjecting thebuilt-up mass to pressure between metallic plates so that the gelatinoussheet stencil is forced inwardly of the face of the screen upon which itrepcses to flow around and substantially encase the wire and mesh of thescreen with the material of the stencil whereby the screen and stencilform a unitary organization.

6. A stencil comprising in combination with a frame, a sheet ofrelatively elastic material secured under tension across said frame andsecured thereto, a fine mesh metallic screen positioned within saidframe and upon said material. and strips of like material, said stripsbeing positioned upon the marginal edges of said screen and in adherenceto said sheet of material and screen so that the marginal edges of thescreen are firmly secured to the said sheet and strips of material, aportion of said sheet being removed from within the area. defined byplacement of said strips whereby tension previously existing in saidsheet of material is in part transferred to said metallic screen, and aremovable figure secured upon said screen, said figure being imperviousto pigments.

'7. A stencil support for industrial use, said support comprising theelements in combination of, a frame, a fabric secured upon said frameunder tension, a fine mesh metallic screen superposed upon said fabricand being bonded to the marginal edges thereof, said fabric having aportion thereof removed from within the area delineated by the bondbetween said fabric and screen whereby tension in said fabric is in parttransferred to said screen, and a figure secured upon said screen, saidfigure being impervious to pigments.

LYMAN H. JOHNSON. PAUL S. JOHNSON.

